secret

1.秘密的；保密的；外人不得而知的known about by only a few people; kept hidden from others

2.[obn]（指行为与习惯）暗中进行的，未公开的，隐秘的used to describe actions and behaviour that you do not tell other people about

3.[nubn]~ (about sth)诡秘；神秘liking to have secrets that other people do not know about; showing this

1.[c]秘密；机密something that is known about by only a few people and not told to others

2.[sing]诀窍；秘诀the best or only way to achieve sth; the way a particular person achieves sth

3.[c][usupl]奥秘；奥妙a thing that is not yet fully understood or that is difficult to understand

in secret

秘密地；暗中without other people knowing about it

1.秘密的;机密的;隐秘的;神秘的

1.秘密

2.奥秘,奥妙

3.秘诀,诀窍;关键

1.deliberately not told to other people, or kept hidden from other people

1.a piece of information that is known only to a few people and is intentionally withheld from general knowledge

2.sth. that is unknown, hidden, or not understood

3.a little-known technique, approach, or piece of information that is the key to success in an endeavor